ZnO Nanowires,Nanotubes, and Complex Hierarchical Structures Obtained by Electrochemical Deposition

Increasing the aspect ratio of ZnO nanostructures is one possible strategy to improve their thermoelectric properties. ZnO nanostructures with one-dimensional (1D) and three-dimensional (3D) morphologies were obtained using electrochemical deposition. Adjusting various deposition parameters made it possible to obtain arrays of vertically aligned ZnO nanowires (NWs) with controlled dimensions, density, and electrical properties. The concentrations of zinc or chloride ions in the solution were found to be key parameters. ZnO NWs were transformed into ZnO nanotubes (NTs), with an increased aspect ratio compared with the NWs, by selectively dissolving the core of the ZnO NWs in a concentrated KCl solution. The aspect ratio was strongly increased when the ZnO NWs were hierarchically organized in a 3D morphology. The synthesis of thin films composed of ordered hollow urchin-like ZnO NW structures was performed by combining the electrochemical deposition and polystyrene sphere templating methods. The electronic properties of the urchin-like ZnO structures were investigated by means of photoluminescence and transmission measurements.     

Design of a computerized scheduling system for best rule analysis and control

A Computerized Scheduling System (CSS) for a gear box manufacturing plant has been developed to simulate a specific manufacturing facility and to analyse conditions that identify bottlenecks during the production process. The model, based partly on practical experience and partly on theoretical work, allows the analyst to concentrate on a single entity (such as a job) and the sequence of events and activities that undergoes as it “passes through” the system. The CSS makes use of actual company data regarding individual machines and operators, and incorporates interarrival times, job types, tasks for each job, routings for the different job types and process time for each job type and specific task. Also, the model provides information on output — average total delay in queue, average number in queue, average utilization and average delay in queue. Although the resultant model was constructed for the application on hand, the principles employed can be extended to include procedures encountered in similar manufacturing environments.     

Fabrication of helically perforated gold, nickel, and polystyrene thin films

Helical microstructures are of interest for MEMS devices because of their spring-like shape. However, helices with micron and submicron dimensions are difficult to engineer using conventional processing techniques where patterning is accomplished lithographically. In this paper, we report the fabrication of porous gold, nickel, and polystyrene thin films with helical pore architectures. All films were made using a replication process, in which a thin film comprised of independent helical microstructures acted as the template. Filling of the template with metals was achieved by electroplating through the microstructures, whereas filling with polystyrene was achieved by capillary action. Porous films were produced from these composites by wet etch removal of the template material. Typical helical pores were on the order of 100 nm in diameter and extended through a film 1 /spl mu/m to 2 /spl mu/m thick. These films were generally more robust than the films from which they were templated, since they consisted of a solid network with helical pores rather than individual structures. Polymer and metal films with helical pores could be used for sensor and catalytic devices that take advantage of the chemical properties of these materials. Polymer films are also of interest for mechanical sensor and actuator devices since they are expected to be more compliant than both traditional MEMS materials and the films from which they were templated.     

The brief abstinence test: Effects of continued incentive availability on cocaine abstinence.

This study compared the effects of 4 voucher incentive conditions of a brief abstinence test on continuous cocaine abstinence. In 3 conditions, cocaine-abusing methadone patients could earn $100 for 2 days of cocaine abstinence; 2 of these conditions offered, on either a continuous or interrupted schedule, an additional $300 for evidence of sustained abstinence over the next 9 days. In the 4th condition, no incentives were available. In incentive conditions, 70-80% of patients initiated abstinence, compared with 48% in the no-incentive condition. Both continuing reinforcement conditions produced higher rates of sustained abstinence than the single and no-voucher conditions. The study confirmed the utility of quantitative urine-testing methods combined with high valued incentives to promote cocaine abstinence initiation in methadone maintenance patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spine injuries in combat troops--Panama, 1989

Operation Just Cause was until recently the largest American combat operation since Vietnam, and remains the largest nighttime parachute operation since World War II. All 252 casualties were airlifted to San Antonio, Texas, for medical treatment. Greater than 80% sustained orthopedic injuries. Sixteen patients were admitted for injuries to the back or neck. Three of the four patients with significant fractures or fracture-dislocations were paraplegic. Two of the three patients with gunshot wounds to the back required extensive reconstruction for wound management. In addition to the 252 casualties, there were 23 fatalities, among whom 7 suffered major injuries to the spine. Spine injuries represented the most significant source of long-term morbidity among those soldiers wounded in combat in Panama, and were common among the fatalities. Noteworthy in these cases was the high percentage of severe neurologic injuries in patients with significant fractures (75%), particularly fractures associated with gunshot wounds. Also of interest were the cases of major soft tissue injury associated with high-velocity gunshot wounds (66%) and the extensive soft tissue surgery needed to treat these injuries.     

Human homologs of Schizosaccharomyces pombe rad1, hus1, and rad9 form a DNA damage-responsive protein complex

DNA damage activates cell cycle checkpoints in yeast and human cells. In the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe checkpoint-deficient mutants have been characterized, and the corresponding genes have been cloned. Searches for human homologs of S. pombe rad1, rad9, and hus1 genes identified the potential human homologs hRad1, hRad9, and hHus1; however, little is known about the roles of these proteins in human cells. The present studies demonstrate that hRad1 and hHus1 associate in a complex that interacts with a highly modified form of hRad9, but hHus1 and hRad1 do not associate with hRad17. In addition to being a key participant in complex formation, hRad9 is phosphorylated in response to DNA damage. Together, these results suggest that hRad9, hRad1, and hHus1 are central components of a DNA damage-responsive protein complex in human cells.     

Voucher-based incentives for cigarette smoking reduction in a women's residential treatment program.

Participants were women (N = 16) living with their children in a residential substance abuse treatment facility. In this within-subjects repeated measures study, a 1-week baseline was followed by a 4-week intervention and a 2-week follow-up (same as the baseline). The intervention consisted of exposure to an educational video and a smoking cessation workbook, brief individual support meetings, and an escalating schedule of voucher-based reinforcement of abstinence. Throughout the study, three daily breath samples (8 a.m., noon, and 4 p.m.) were collected Monday through Friday to determine carbon monoxide (CO) concentration. In addition, urine cotinine (COT) was assessed on Monday mornings to monitor weekend tobacco use. Participants received vouchers of escalating value for CO-negative breath and COT-negative urine samples. Positive samples reset the voucher value. Significantly more negative tests were submitted during the intervention than during baseline and follow-up. The intensive behavioral intervention evaluated in this study produced a substantial reduction in cigarette smoking, and 25% of participants remained abstinent 2 weeks after the intervention was suspended. Nevertheless, the percentage of CO-negative samples submitted during the follow-up returned to baseline levels. While retaining many real-world characteristics, residential treatment facilities provide important opportunities for smoking cessation treatment and research.     

Characterisation of a new bioadhesive system based on polysaccharides with the potential to be used as bone glue

Although gluing bone is in theory a very attractive alternative to classical fracture treatment, this method is not yet clinically established due to the lack of an adhesive which would meet all the necessary requirements. We therefore developed a novel two-component bioadhesive system with the potential to be used as a bone adhesive based on biocompatible and degradable biopolymers (chitosan, oxidised dextran or starch). After mixing in water, the two components covalently cross-link by forming a Schiff’s base. By the same mechanism, the glue binds to any other exposed amino group such as for example those exposed in fractured bone, even in the presence of water. Modified chitosan was synthesised from commercially available chitosan by deacetylation and was then reduced in molecular weight by heating in acid. The amount of free amino groups was analysed by IR. The molecular weight was determined by viscosimetry. Starch or dextran were oxidised with periodic acid to generate aldehyde groups, which were quantified by titration. l-Dopa was conjugated to oxidised dextran or starch in analogy to the gluing mechanism of mussels. Biomechanical studies revealed that the new glue is superior to fibrin glue, but has less adhesive strength than cyanoacrylates. In vitro cell testing demonstrated excellent biocompatibility, rendering this glue a potential candidate for clinical use.     

Hyperbolic Penalty: A New Method for Nonlinear Programming with Inequalities

This work intends to present and to analyze a new penalty method that purposes to solve the general nonlinear programming problem subject to inequality constraints. The proposed method has the important feature of being completely differentiable and combines features of both exterior and interior penalty methods. Numerical results for some problems are commented on.